Provable data integrity verifying method, apparatuses and system

Abstract

The present invention proposes a Provable Data Integrity (PDI) verifying method, in which data are firstly fingerprinted at a client, and the fingerprints are sent to an archive along with the data; when necessary, the client sends a “challenge” to the archive so as to determine the integrity of the data, and the archive proves the integrity of the data by using the received fingerprints; and finally, the client verifies the integrity of the data based on the output from the archive in response to the “challenge”.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of Invention[0002]The present invention relates to the field of storage network security, and more particularly, to a Provable Data Integrity (PDI) verifying method, apparatuses and system.[0003]2. Description of Prior Art[0004]The Internet is fast evolving toward outsourcing data from one's local storage to global-scale persistent storage service. The Amazon Simple Storage Service (Amazon S3) (Reference 1: Amazon Simple Storage Service (Amazon S3), http: / / aws.amazon.com / s3) is one of such storage system for the Internet. Amazon S3 provides web services interface that can be used to store and retrieve data. The service of Amazon S3 is global-scale and business-class while its pricing is quite reasonable, US $0.15 per GB / Month of storage used, US $0.10 per GB for all data transfer in, and US $0.18 per GB for the first 10 TB / month data transfer out. In case someone is seeking for free global-scale storage service, there are as well. MediaMax (...

AI Technical Summary

Benefits of technology

[0063]The inventive PDI scheme can ensure data integrity of the data at overwhelming probability, for instance 1-2−64. Compared to prior arts that achieve (1) data integrity is ensured on each bit of the data, (2) the size of the challenge that the client sends to the archive is constant, and (3) the size of the data integrity proof that the archive sends to the client is constant, the inventive PDI scheme has following four main advantages.

Problems solved by technology

However, provision of high bandwidth from remote archive to the client verifier is impractical at present and in the near future as well.

In particular, it's hard for a mobile client to enjoy high bandwidth connection.

In such case, the third-party verifier should not have access to the user data; otherwise it may violate the user data privacy.

The size of the archive storage that the fingerprint of data consumes

The naïve solution has drawback in that its communication complexity is linear with respect to the queried data size.

Moreover, in the case of a third-party verifier, sending user data to the verifier is prohibitive because it violates the data owner's privacy.

However, this way the number a particular data can be verified is limited by the number of secret keys that has to be fixed a priori.

The proposals of References 5 and 6 have drawback in that the archive has to exponentiate the entire file.

The S-PDP scheme has one problem in that its design goal, i.e. sampling, may sometimes be meaningless to the data owner.

However, there are many types of files that cannot withstand even one bit error.

For example, loss of the head of a media file, where codec configuration parameters resides, will cause difficulty in rendering.

For another example, damage on the (public key encrypted) symmetric encryption key that is embedded in an encrypted file results in garbage ciphertext that no one can recover the plaintext anymore.

The S-PDP scheme has another problem in that it is extremely inefficient for being adopted by a third-party verification (or so-called public verifiability) system.

The consequence is a huge amount of file blocks, for each of which there must be a tag being generated.

In other words, the size of the tags is two times larger than the file itself and the time it costs the client to tag a file is too much to be practically doable.

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